U.S. patent application number 17/204181 was filed with the patent office on 2021-07-01 for use of polyvinylacetate polymers or copolymers to increase the viscosity of the isocyanate component of a two-component curable polymeric system.
The applicant listed for this patent is Henkel IP & Holding GmbH. Invention is credited to Zachary Bryan, Chih-Min Cheng, Shuhua Jin, Li Kang, James Murray.
Application Number | 20210198471 17/204181 |
Document ID | / |
Family ID | 1000005477097 |
Filed Date | 2021-07-01 |
United States Patent
Application |
20210198471 |
Kind Code |
A1 |
Cheng; Chih-Min ; et
al. |
July 1, 2021 |
USE OF POLYVINYLACETATE POLYMERS OR COPOLYMERS TO INCREASE THE
VISCOSITY OF THE ISOCYANATE COMPONENT OF A TWO-COMPONENT CURABLE
POLYMERIC SYSTEM
Abstract
Disclosed is a two-component curable polymeric system having
increased viscosity. One component contains a homogeneous blend of
a polyisocyanate and a homopolymer or copolymer of vinyl acetate.
This component has a higher viscosity than the polyisocyanate
alone, thereby increasing the viscosity of the two-component
curable system. The other component of the two-component curable
system is a composition containing an isocyanate reactive
component. The polyisocyanate and the isocyanate reactive component
react together ("cure") to form a polymer. Typically, but not
always, the isocyanate reactive component is a polyol or polyamine
that is capable of reacting with the polyisocyanate, thereby
forming a polyurethane (polyol) or polyurea (polyamine).
Inventors: |
Cheng; Chih-Min; (Westford,
MA) ; Bryan; Zachary; (Middletown, CT) ;
Murray; James; (Newmarket, NH) ; Kang; Li;
(Middletown, CT) ; Jin; Shuhua; (Cheshire,
CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Henkel IP & Holding GmbH |
Duesseldorf |
|
DE |
|
|
Family ID: |
1000005477097 |
Appl. No.: |
17/204181 |
Filed: |
March 17, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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PCT/US2019/053701 |
Sep 28, 2019 |
|
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17204181 |
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62738070 |
Sep 28, 2018 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08L 75/06 20130101;
C08L 31/04 20130101; C08L 2205/03 20130101 |
International
Class: |
C08L 31/04 20060101
C08L031/04; C08L 75/06 20060101 C08L075/06 |
Claims
1. A two-component curable composition comprising: a component A
comprising at least one isocyanate-reactive composition, and a
component B, wherein component B is an isocyanate functional
composition comprising: a) an isocyanate material comprising a
polyisocyanate, wherein the polyisocyanate has an average
isocyanate functionality of at least 2 and has a viscosity measured
on a Brookfield viscometer at 20 RPM with spindle 6 at 25.degree.
C.; and b) a polymer comprising, as polymerized units, vinyl
acetate; wherein component B is a homogeneous mixture and wherein
component B has a component B viscosity measured on a Brookfield
viscometer at 20 RPM with spindle 6 at 25.degree. C.
2. The two-component curable composition according to claim 1,
wherein the isocyanate-reactive composition in component A
comprises at least one compound selected from polyol, polyamine,
polythiol, aminoalcohol, and mixtures thereof.
3. The two-component curable composition according to claim 1,
wherein the isocyanate-reactive composition in component A
comprises a polyol.
4. The two-component curable composition according to any of claim
1, wherein the polyisocyanate comprises methylene diphenyl
diisocyanate.
5. The composition according to any of claim 1, wherein the
polyisocyanate comprises polymeric polyisocyanate.
6. The two-component curable composition according to claim 1,
wherein the component B viscosity is in the range of 500 mPasec to
300,000 mPasec.
7. The two-component curable composition according to claim 1,
wherein the polymer comprises, as polymerized units, at least 50%
by weight of vinyl acetate.
8. The two-component curable composition according to claim 1,
wherein the polymer further comprises, as polymerized units, vinyl
chloride.
9. The two-component curable composition according to claim 1,
wherein component A and component B are present in a stoichiometric
ratio of 1.0:0.90 to 1.0:1.40 based on the number of moles of
isocyanate-reactive groups in component A and the number of moles
of isocyanate groups in component B.
10. The composition according to claim 1, wherein the isocyanate
material is a pre-polymer comprising methylene diphenyl
diisocyanate.
11. The composition according to claim 1, wherein the
polyisocyanate has been reacted with a urethane to afford an
allophanate.
12. The composition according to claim 1, wherein the composition
viscosity is at least 1000 mPasec at a temperature of 25.degree.
C.
13. The two-component curable composition according to claim 1,
wherein the polymer comprises a copolymer of vinyl acetate and
vinyl chloride.
Description
FIELD OF THE INVENTION
[0001] This invention relates to two-component curable polyurethane
systems. One component of such systems comprises a polyisocyanate
comprising an average of at least two isocyanate functionalities
per molecule. The other component of the two-component system is a
composition comprising an isocyanate reactive component. The two
components must be stored separately. The two components are mixed
just before use and react together ("cure") to form a polymer,
generally in 1 to 8 hours or in some cases as long as 72 hours
after mixing. Typically, but not always, the isocyanate reactive
component is a polyol or polyamine that is capable of reacting with
the polyisocyanate, thereby forming a polyurethane (if a polyol is
reacted) or polyurea (if a polyamine is reacted). Specifically,
this invention relates to increasing the viscosity of the
polyisocyanate component of these two-component curable
polyurethane systems, thereby also increasing the viscosity of the
mixed two-component curable polyurethane system.
BACKGROUND OF THE INVENTION
[0002] Mixed two-component curable polyurethane adhesive systems
can be applied using a number of methods. Viscosity of the newly
mixed adhesive will be a composite of the viscosity of each
component. Each application method will require the newly mixed
adhesive to be within a defined viscosity range for successful use;
below this range the applied mixture will spread and run and above
this range the mixed adhesive may not apply evenly or at all.
Two-component curable polyurethane systems have traditionally
relied on modification of the polyol component to effectively
increase the viscosity or "thicken" mixtures of the two components.
There currently are very few options available to effectively
thicken the polyisocyanate component. The most common method of
increasing viscosity of the polyisocyanate component is to make an
isocyanate functional pre-polymer, but prepolymer production
requires special reaction processes and equipment and prepolymer
use may raise TSCA (Toxic Substances Control Act) or other
regulatory concerns. Production of a pre-polymer can introduce
repeatability issues as well. Other common techniques for
increasing viscosity of the polyisocyanate component include
incorporating materials like silica into the polyisocyanate
component. However, silica thixotropes when mixed with
polyisocyanates introduce shear thinning properties, can react with
the isocyanate, and lead to de-gassing issues.
[0003] Until now, there have been few efforts to determine the
effect on physical properties of mixed two-component adhesives
having polyvinyl acetate polymers and copolymers blended in
significant amounts with the polyisocyanate component of these
two-component adhesives.
SUMMARY OF THE INVENTION
[0004] The inventors have unexpectedly discovered that polyvinyl
acetate homopolymer and copolymers are not only compatible but form
a homogeneous mixture with the polyisocyanate that remained stable
indefinitely. Furthermore, the vinyl acetate homopolymer or
copolymer with vinyl chloride surprisingly increased the viscosity
of the polyisocyanate component of two-component curable polymer
systems, while maintaining a Newtonian viscosity. Two-component
polyurethane systems incorporating the vinyl acetate homopolymer or
copolymer with vinyl chloride in the polyisocyanate component can
be used for such applications as potting, coatings, and adhesives,
for instance. Due to the Newtonian viscosity characteristics, such
systems are particularly suitable for potting compounds, where the
Newtonian viscosity imparts a "self-leveling" property. The
adhesion of such systems, if used as adhesives, was not
significantly degraded beyond the expected effect of dilution of
the polyisocyanate component due to the addition of the vinyl
acetate homopolymer or copolymer with vinyl chloride material.
[0005] One embodiment comprises a polyisocyanate component for a
two-component polyurethane composition which is a homogeneous
mixture comprising: a) a polyisocyanate; and b) a polymer
comprising vinyl acetate as polymerized units.
[0006] In one embodiment the polyisocyanate a) has an average
isocyanate functionality of at least 2 and has a viscosity of at
least 10 mPasec measured on a DV-Ill Brookfield Viscometer using RV
spindle 6, at either 2 RPM or 20 RPM, conditioned for at least 12
hours at 25.degree. C. with RV Spindle 6, prior to the addition of
the polymer comprising vinyl acetate as polymerized units. The
homogeneous polyisocyanate component comprising a) and b) has a
viscosity measured on a DV-Ill Brookfield Viscometer using RV
spindle 6, at either 2 RPM or 20 RPM, conditioned for at least 12
hours at 25.degree. C. with RV Spindle 6 of at least 250
mPasec.
[0007] In certain embodiments, the viscosity of the mixture of a)
and b) was 600 times higher (under the same conditions) than the
viscosity of a) alone.
[0008] In other embodiments the viscosity of the composition a) and
b) remained generally Newtonian even with the significant increase
in viscosity.
[0009] The invention also encompasses a two-component polyurethane
system, including A) a first isocyanate reactive component and B) a
second component comprising a mixture of polyisocyanate and a
copolymer comprising vinyl acetate and vinyl chloride as
polymerized units.
[0010] The invention is also directed to the homogenously mixed
two-component polyurethane composition comprising A) a first
isocyanate reactive component; and B) a second component comprising
a mixture of polyisocyanate and a polymer comprising vinyl acetate
as polymerized units and/or a copolymer comprising vinyl acetate
and vinyl chloride as polymerized units; and the reaction product
of this mixture of A) and B).
[0011] Within this specification, embodiments have been described
in a way which enables a clear and concise specification to be
written, but it is intended and will be appreciated that
embodiments may be variously combined or separated without parting
from the invention. For example, it will be appreciated that all
preferred features described herein are applicable to all aspects
of the invention described herein.
BRIEF DESCRIPTION OF THE FIGURES
[0012] FIG. 1 shows the viscosity of a composition according to one
embodiment of the invention;
[0013] FIG. 2 shows the viscosity of a composition according to
another embodiment of the invention; and
[0014] FIG. 3 shows the viscosity of a composition according to
still another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as is commonly understood by one
of ordinary skill in the art. As used herein for each of the
various embodiments, the following definitions apply.
[0016] "Alkyl" or "alkane" refers to a hydrocarbon chain or group
containing only single bonds between the chain carbon atoms. The
alkane can be a straight hydrocarbon chain or a branched
hydrocarbon group. The alkane can be cyclic. The alkane can contain
1 to 20 carbon atoms, advantageously 1 to 10 carbon atoms and more
advantageously 1 to 6 carbon atoms. In some embodiments the alkane
can be substituted. Exemplary alkanes include methyl, ethyl,
n-propyl, isopropyl, isobutyl, n-butyl, sec-butyl, tert-butyl,
isopentyl, neopentyl, tert-pentyl, isohexyl and decyl.
[0017] "Alkenyl" or "alkene" refers to a hydrocarbon chain or group
containing one or more double bonds between the chain carbon atoms.
The alkenyl can be a straight hydrocarbon chain or a branched
hydrocarbon group. The alkene can be cyclic. The alkene can contain
1 to 20 carbon atoms, advantageously 1 to 10 carbon atoms and more
advantageously 1 to 6 carbon atoms. The alkene can be an allyl
group. The alkene can contain one or more double bonds that are
conjugated. In some embodiments the alkene can be substituted.
[0018] "Alkoxy" refers to the structure --OR, wherein R is
hydrocarbyl.
[0019] "Alkyne" or "alkynyl" refers to a hydrocarbon chain or group
containing one or more triple bonds between the chain carbon atoms.
The alkyne can be a straight hydrocarbon chain or a branched
hydrocarbon group. The alkyne can be cyclic. The alkyne can contain
1 to 20 carbon atoms, advantageously 1 to 10 carbon atoms and more
advantageously 1 to 6 carbon atoms. The alkyne can contain one or
more triple bonds that are conjugated. In some embodiments the
alkyne can be substituted.
[0020] "Amine" refers to a molecule comprising at least one --NHR
group wherein R can be a covalent bond, H, hydrocarbyl or
polyether. In some embodiments an amine can comprise a plurality of
--NHR groups.
[0021] "Aryl" or "Ar" refers to a monocyclic or multicyclic
aromatic group. The cyclic rings can be linked by a bond or fused.
The aryl can contain from 6 to about 30 carbon atoms;
advantageously 6 to 12 carbon atoms and in some embodiments 6
carbon atoms. Exemplary aryls include phenyl, biphenyl and
naphthyl. In some embodiments the aryl is substituted.
[0022] "Ester" refers to the structure R--C(O)--O--R' where R and
R' are independently selected hydrocarbyl groups with or without
heteroatoms. The hydrocarbyl groups can be substituted or
unsubstituted.
[0023] "Halogen" or "halide" refers to an atom selected from
fluorine, chlorine, bromine and iodine.
[0024] "Hetero" refers to one or more heteroatoms in a structure.
Exemplary heteroatoms are independently selected from N, O and
S.
[0025] "Heteroaryl" refers to a monocyclic or multicyclic aromatic
ring system wherein one or more ring atoms in the structure are
heteroatoms. Exemplary heteroatoms are independently selected from
N, O and S. The cyclic rings can be linked by a bond or fused. The
heteroaryl can contain from 5 to about 30 carbon atoms;
advantageously 5 to 12 carbon atoms and in some embodiments 5 to 6
carbon atoms. Exemplary heteroaryls include furyl, imidazolyl,
pyrimidinyl, tetrazolyl, thienyl, pyridyl, pyrrolyl, thiazolyl,
isothiazolyl, oxazolyl, isoxazolyl, thiazolyl, quinolinyl and
isoquinolinyl. In some embodiments the heteroaryl is
substituted.
[0026] "Hydrocarbyl" refers to a group containing carbon and
hydrogen atoms. The hydrocarbyl can be linear, branched, or cyclic
group. The hydrocarbyl can be alkyl, alkenyl, alkynyl or aryl. In
some embodiments, the hydrocarbyl is substituted.
[0027] "(Meth)acrylate" refers to acrylate and methacrylate.
[0028] "Molecular weight" refers to weight average molecular weight
unless otherwise specified. The number average molecular weight
M.sub.n, as well as the weight average molecular weight M.sub.w, is
determined according to the present invention by gel permeation
chromatography (GPC, also known as SEC) at 23.degree. C. using a
styrene standard. This method is known to one skilled in the art.
The polydispersity is derived from the average molecular weights
M.sub.w and M.sub.n. It is calculated as PD=M.sub.w/M.sub.n.
Polydispersity indicates the width of the molecular weight
distribution and thus of the different degrees of polymerization of
the individual chains in polydisperse polymers. For many polymers
and polycondensates, a polydispersity value of about 2 applies.
Strict monodispersity would exist at a value of 1. A low
polydispersity of, for example, less than 1.5 indicates a
comparatively narrow molecular weight distribution.
[0029] "Oligomer" refers to a defined, small number of repeating
monomer units such as 2-5,000 units, and advantageously 10-1,000
units which have been polymerized to form a molecule. Oligomers are
a subset of the term polymer.
[0030] "Polyether" refers to polymers which contain multiple ether
groups (each ether group comprising an oxygen atom connected top
two hydrocarbyl groups) in the main polymer chain. The repeating
unit in the polyether chain can be the same or different. Exemplary
polyethers include homopolymers such as polyoxymethylene,
polyethylene oxide, polypropylene oxide, polybutylene oxide,
polytetrahydrofuran, and copolymers such as poly(ethylene oxide co
propylene oxide), and EO tipped polypropylene oxide.
[0031] "Polyester" refers to polymers which contain multiple ester
linkages. A polyester can be either linear or branched.
[0032] "Polymer" refers to any polymerized product greater in chain
length and molecular weight than the oligomer. Polymers can have a
degree of polymerization of about 20 to about 25000. As used herein
polymer includes oligomers and polymers.
[0033] "Polyol" refers to the molecule comprising two or more --OH
groups.
[0034] "Substituted" refers to the presence of one or more
substituents on a molecule in any possible position. Useful
substituents are those groups that do not significantly diminish
the disclosed reaction schemes. Exemplary substituents include, for
example, H, halogen, (meth)acrylate, epoxy, oxetane, urea,
urethane, N.sub.3, NCS, CN, NCO, NO.sub.2, NX.sup.1X.sup.2,
OX.sup.1, C(X.sup.1).sub.3, C(halogen).sub.3, COOX.sup.1, SX.sup.1,
Si(OX.sup.1)iX.sup.2.sub.3-i, alkyl, alcohol, alkoxy; wherein
X.sup.1 and X.sup.2 each independently comprise H, alkyl, alkenyl,
alkynyl or aryl and i is an integer from 0 to 3.
[0035] "thiol" refers to a molecule comprising at least one --SH
group. In some embodiments a thiol can comprise a plurality of --SH
groups.
[0036] This invention relates to two-component or two-part curable
polymeric systems. One component of such systems is a
polyisocyanate component. The other component of the two-part
curable polymeric system comprises an isocyanate reactive material
that is capable of reacting with the polyisocyanate material to
form a cured polymeric material.
[0037] Polyvinyl acetate or copolymers thereof, especially
copolymers comprising vinyl chloride in addition to vinyl acetate
as polymerized units are effective at increasing the viscosity of
polyisocyanates and surprisingly effective at increasing viscosity
of methylene diphenyl diisocyanate (MDI) based polyisocyanates
including but not limited to polymeric MDI, polyisocyanate
pre-polymers, modified polyisocyanate pre-polymers, MDI
pre-polymers, allophanates of MDI, and modified MDI
pre-polymers.
[0038] The term "pre-polymer" in this disclosure is understood to
mean a material that is synthesized by reacting a stoichiometric
excess of a polyisocyanate with a polyisocyanate reactive material,
such that the resulting material retains unreacted isocyanate
groups.
[0039] As an example, for a polyisocyanate reacting with a polyol,
"stoichiometric excess" is understood to mean that there are more
equivalents of isocyanate functionality from the polyisocyanate
compound than equivalents of hydroxyl functionality from the polyol
present during reaction to form the pre-polymer. All of the polyol
is reacted and the resulting polyisocyanate pre-polymers comprise
reactive isocyanate groups. In this disclosure, it is to be
understood that the term "polyisocyanate pre-polymer" is applied to
any compound made according to the foregoing description, i.e., as
long as the compound is made with a stoichiometric excess of
isocyanate groups to hydroxyl groups, it is a pre-polymer.
[0040] The polymers comprising as polymerized units, either vinyl
acetate or vinyl acetate and vinyl chloride described herein, when
blended together to for a homogenous mixture with the
polyisocyanate component can effectively increase the viscosity of
the polyisocyanate component without introducing shear thinning
characteristics and is shown to increase the viscosity of the
polyisocyanate as much as 6000% compared to polyisocyanate without
added polymers.
Polyisocyanate Component
[0041] The polyisocyanate component comprises polymeric
diphenylmethanediisocyante (MDI), isocyanate functional
pre-polymer, or mixtures thereof. Such components are understood to
have on average two or more isocyanate groups. Polymeric MDI is a
known commercially available variant of MDI. It is not a
pre-polymer but rather "linked" MDI molecules. Polyisocyanate
components that are 100% monomeric polyisocyanates do not show the
surprising advantages. However, polyisocyanate components
comprising up to about 50% by weight monomeric polyisocyanates do
show advantageous properties. In some embodiments the
polyisocyanate component comprises about 50% or less by weight
monomeric polyisocyanates by weight of the polyisocyanate
component. Monomeric MDI and its isomers are preferred and may be
used exclusively if monomeric polyisocyanates are present in the
polyisocyanate component. In some embodiments the polyisocyanate
component preferably comprises polymeric MDI, a MDI pre-polymer,
monomeric MDI or mixtures thereof.
[0042] Some suitable polyisocyanates useful for preparing the
isocyanate functional pre-polymers include hydrogenated MDI (HMDI),
xylylene diisocyanate (XDI), tetramethyl xylylene diisocyanate
(TMXDI), 4,4'-diphenyl dimethyl-methane diisocyanate, di- and
tetraalkylene diphenylmethane diisocyanate, 4,4'-dibenzyl
diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene
diisocyanate, 1-methyl-2,4-diisocyanatocyclohexane,
1,6-diiso-cyanato-2,2,4-trimethyl hexane,
1,6-diisocyanato-2,4,4-trimethyl hexane,
1-isocyanatomethyl-3-isocyanato-1,5,5-trimethyl cyclohexane (IPDI),
chlorinated and brominated diisocyanates, phosphorus-containing
diisocyanates, 4,4'-diisocyanatophenyl perfluoroethane,
tetramethoxybutane-1,4-diisocyanate, butane-1,4-diisocyanate,
hexane-1,6-diisocyanate (HDI), dicyclohexylmethane diisocyanate,
cyclo-hexane-1,4-diisocyanate, ethylene diisocyanate, phthalic
acid-bis-isocyanatoethyl ester; diisocyanates containing reactive
halogen atoms, such as 1-chloromethylphenyl-2,4-diisocyanate,
1-bromomethylphenyl-2,6-diisocyanate or
3,3-bis-chloromethylether4,4'-diphenyl diisocyanate, trimethyl
hexamethylene diisocyanate, 1,4-diisocyanatobutane,
1,12-diisocyanatododecane, dimer fatty acid diisocyanate,
tetramethylene diisocyanate, hexamethylene diisocyanate, undecane
diisocyanate, dodecamethylene diisocyanate,
2,2,4-trimethylhexane-2,3,3-trimethylhexamethylene diisocyanate,
1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-
and 1,4-tetramethyl xylene diisocyanate, isophorone,
4,4-dicyclohexylmethane, tetramethylxylylene (TMXDI) and lysine
ester diisocyanate.
[0043] Some suitable polyisocyanates include aromatic
polyisocyanates. Aromatic polyisocyanates are characterized by the
fact that the isocyanate groups are positioned directly on the
benzene ring. Suitable aromatic diisocyanates include 4,4'-diphenyl
methane diisocyanate (MDI) and its isomers, toluene diisocyanate
(TDI) and its isomers and naphthalene-1,5-diisocyanate (NDI).
[0044] Some suitable polyisocyanates include sulfur-containing
polyisocyanates that are obtained, for example, by reaction of 2
mol hexamethylene diisocyanate with 1 mol thiodiglycol or
dihydroxydihexyl sulfide.
[0045] Aliphatic polyisocyanates with two or more isocyanate
functionality formed by biuret linkage, uretdione linkage,
allophanate linkage, and/or by trimerization are suitable.
[0046] Suitable at least trifunctional polyisocyanates are
polyisocyanates formed by trimerization or oligomerization of
diisocyanates or by reaction of diisocyanates with polyfunctional
compounds containing hydroxyl or amino groups. Isocyanates suitable
for the production of trimers are the diisocyanates mentioned
above, the trimerization products of HDI, MDI, TDI or IPDI being
particularly preferred.
[0047] The polyisocyanate component encompasses a single
polyisocyanate or the mixture of two or more polyisocyanates.
Isocyanate Reactive Component
[0048] As used herein an isocyanate reactive compound is a compound
containing functional moieties that will react with an isocyanate
moiety. The isocyanate reactive component can be a single compound
comprising an alcohol moiety, an amine moiety, a thiol moiety, or a
compound with a combination of these moieties. The isocyanate
reactive component can be a mixture of compounds with each compound
comprising one or more moieties independently selected from
alcohol, amine, thiol and am inoalcohol.
[0049] In one embodiment the isocyanate reactive component can be a
polyol. A polyol is understood to be a compound containing more
than one OH group in the molecule. A polyol can further have other
functionalities on the molecule. The term "polyol" encompasses a
single polyol or a mixture of two or more polyols.
[0050] Some suitable polyol components include aliphatic alcohols
containing 2 to 8 OH groups per molecule. The OH groups may be both
primary and secondary. Some suitable aliphatic alcohols include,
for example, ethylene glycol, propylene glycol, butane-1,4-diol,
pentane-1,5-diol, hexane-1,6-diol, heptane-1,7-diol,
octane-1,8-diol and higher homologs or isomers thereof which the
expert can obtain by extending the hydrocarbon chain by one CH2
group at a time or by introducing branches into the carbon chain.
Also suitable are higher alcohols such as, for example, glycerol,
trimethylol propane, pentaerythritol and oligomeric ethers of the
substances mentioned either individually or in the form of mixtures
of two or more of the ethers mentioned with one another.
[0051] Some suitable polyols include the reaction products of low
molecular weight polyhydric alcohols with alkylene oxides,
so-called polyether polyols. The alkylene oxides preferably contain
2 to 4 carbon atoms. Some reaction products of this type include,
for example, the reaction products of ethylene glycol, propylene
glycol, the isomeric butane diols, hexane diols or
4,4'-dihydroxydiphenyl propane with ethylene oxide, propylene oxide
or butylene oxide or mixtures of two or more thereof. The reaction
products of polyhydric alcohols, such as glycerol, trimethylol
ethane or trimethylol propane, pentaerythritol or sugar alcohols or
mixtures of two or more thereof, with the alkylene oxides mentioned
to form polyether polyols are also suitable. Thus, depending on the
desired molecular weight, products of the addition of only a few
mol ethylene oxide and/or propylene oxide per mol or of more than
one hundred mol ethylene oxide and/or propylene oxide onto low
molecular weight polyhydric alcohols may be used. Other polyether
polyols are obtainable by condensation of, for example, glycerol or
pentaerythritol with elimination of water. Some suitable polyols
include those polyols obtainable by polymerization of
tetrahydrofuran.
[0052] The polyethers are reacted in known manner by reacting the
starting compound containing a reactive hydrogen atom with alkylene
oxides, for example ethylene oxide, propylene oxide, butylene
oxide, styrene oxide, tetrahydrofuran or epichlorohydrin or
mixtures of two or more thereof.
[0053] Suitable starting compounds are, for example, water,
ethylene glycol, 1,2- or 1,3-propylene glycol, 1,4- or 1,3-butylene
glycol, hexane-1,6-diol, octane-1,8-diol, neopentyl glycol,
1,4-hydroxymethyl cyclohexane, 2-methyl propane-1,3-diol, glycerol,
trimethylol propane, hexane-1,2,6-triol, butane-1,2,4-triol,
trimethylol ethane, pentaerythritol, mannitol, sorbitol, methyl
glycosides, sugars, phenol, isononylphenol, resorcinol,
hydroquinone, 1,2,2- or 1,1,2-tris-(hydroxyphenyl)-ethane, ammonia,
methyl amine, ethylenediamine, tetra- or hexamethylenediamine,
triethanolamine, aniline, phenylenediamine, 2,4- and
2,6-diaminotoluene and polyphenylpolymethylene polyamines, which
may be obtained by aniline/formaldehyde condensation, or mixtures
of two or more thereof.
[0054] Some suitable polyols include diol EO/PO (ethylene
oxide/propylene oxide) block copolymers, EO-tipped polypropylene
glycols, or alkoxylated bisphenol A.
[0055] Some suitable polyols include polyether polyols modified by
vinyl polymers. These polyols can be obtained, for example, by
polymerizing styrene or acrylonitrile or mixtures thereof in the
presence of polyetherpolyol.
[0056] Some suitable polyols include polyester polyols. For
example, it is possible to use polyester polyols obtained by
reacting low molecular weight alcohols, more particularly ethylene
glycol, diethylene glycol, neopentyl glycol, hexanediol,
butanediol, propylene glycol, glycerol or trimethylol propane, with
caprolactone. Other suitable polyhydric alcohols for the production
of polyester polyols are 1,4-hydroxymethyl cyclohexane, 2-methyl
propane-1,3-diol, butane-1,2,4-triol, triethylene glycol,
tetraethylene glycol, polyethylene glycol, dipropylene glycol,
polypropylene glycol, dibutylene glycol and polybutylene
glycol.
[0057] Some suitable polyols include polyester polyols obtained by
polycondensation. Thus, dihydric and/or trihydric alcohols may be
condensed with less than the equivalent quantity of dicarboxylic
acids and/or tricarboxylic acids or reactive derivatives thereof to
form polyester polyols. Suitable dicarboxylic acids are, for
example, adipic acid or succinic acid and higher homologs thereof
containing up to 16 carbon atoms, unsaturated dicarboxylic acids,
such as maleic acid or fumaric acid, cyclohexane dicarboxylic acid
(CHDA), and aromatic dicarboxylic acids, more particularly the
isomeric phthalic acids, such as phthalic acid, isophthalic acid or
terephthalic acid. Citric acid and trimellitic acid, for example,
are also suitable tricarboxylic acids. The acids mentioned may be
used individually or as mixtures of two or more thereof. Polyester
polyols of at least one of the dicarboxylic acids mentioned and
glycerol which have a residual content of OH groups are suitable.
Suitable alcohols include but not limited to propylene glycol,
butane diol, pentane diol, hexanediol, ethylene glycol, diethylene
glycol, triethylene glycol, dipropylene glycol, tripropylene
glycol, cyclohexanedimethanol (CHDM), 2-methyl-1,3-propanediol
(MPDiol), or neopentyl glycol or isomers or derivatives or mixtures
of two or more thereof. High molecular weight polyester polyols may
be used in the second synthesis stage and include, for example, the
reaction products of polyhydric, preferably dihydric, alcohols
(optionally together with small quantities of trihydric alcohols)
and polybasic, preferably dibasic, carboxylic acids. Instead of
free polycarboxylic acids, the corresponding polycarboxylic
anhydrides or corresponding polycarboxylic acid esters with
alcohols preferably containing 1 to 3 carbon atoms may also be used
(where possible). The polycarboxylic acids may be aliphatic,
cycloaliphatic, aromatic or heterocyclic or both. They may
optionally be substituted, for example by alkyl groups, alkenyl
groups, ether groups or halogens. Suitable polycarboxylic acids
are, for example, succinic acid, adipic acid, suberic acid, azelaic
acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic
acid, trimellitic acid, phthalic anhydride, tetrahydrophthalic
anhydride, hexahydrophthalic anhydride, tetrachlorophthalic
anhydride, endomethylene tetrahydrophthalic anhydride, glutaric
anhydride, maleic acid, maleic anhydride, fumaric acid, dimer fatty
acid or trimer fatty acid or mixtures of two or more thereof. Small
quantities of monofunctional fatty acids may optionally be present
in the reaction mixture.
[0058] The polyester polyol may optionally contain a small number
of terminal carboxyl groups. Polyesters obtainable from lactones,
for example based on -caprolactone (also known as
"polycaprolactones"), or hydroxycarboxylic acids, for example
.omega.-hydroxycaproic acid, may also be used.
[0059] Polyester polyols of oleochemical origin may also be used.
Oleochemical polyester polyols may be obtained, for example, by
complete ring opening of epoxidized triglycerides of a fatty
mixture containing at least partly olefinically unsaturated fatty
acids with one or more alcohols containing 1 to 12 carbon atoms and
subsequent partial transesterification of the triglyceride
derivatives to form alkyl ester polyols with 1 to 12 carbon atoms
in the alkyl group.
[0060] Some suitable polyols include C36 dimer diols and
derivatives thereof. Some suitable polyols include castor oil and
derivatives thereof. Some suitable polyols include fatty polyols,
for example the products of hydroxylation of unsaturated or
polyunsaturated natural oils, the products of hydrogenations of
unsaturated and polyunsaturated polyhydroxy natural oils,
polyhydroxyl esters of alkyl hydroxyl fatty acids, polymerized
natural oils, soybean polyols, and alkylhydroxylated amides of
fatty acids. Some suitable polyols include the hydroxy functional
polybutadienes known, for example, by the commercial name of
"Poly-bd.RTM." available from Cray Valley USA, LLC Exton, Pa. Some
suitable polyols include polyisobutylene polyols. Some suitable
polyols include polyacetal polyols. Polyacetal polyols are
understood to be compounds obtainable by reacting glycols, for
example diethylene glycol or hexanediol or mixtures thereof, with
formaldehyde. Polyacetal polyols may also be obtained by
polymerizing cyclic acetals. Some suitable polyols include
polycarbonate polyols. Polycarbonate polyols may be obtained, for
example, by reacting diols, such as propylene glycol,
butane-1,4-diol or hexane-1,6-diol, diethylene glycol, triethylene
glycol or tetraethylene glycol or mixtures of two or more thereof,
with diaryl carbonates, for example diphenyl carbonate, or
phosgene. Some suitable polyols include polyamide polyols.
[0061] Some suitable polyols include polyacrylates containing OH
groups. These polyacrylates may be obtained, for example, by
polymerizing ethylenically unsaturated monomers bearing an OH
group. Such monomers are obtainable, for example, by esterification
of ethylenically unsaturated carboxylic acids and dihydric
alcohols, the alcohol generally being present in a slight excess.
Ethylenically unsaturated carboxylic acids suitable for this
purpose are, for example, acrylic acid, methacrylic acid, crotonic
acid or maleic acid. Corresponding OH-functional esters are, for
example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate,
2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate,
3-hydroxypropyl acrylate or 3-hydroxypropyl methacrylate or
mixtures of two or more thereof.
[0062] The isocyanate reactive component can be a compound
comprising an amine moiety. The amine moieties can be primary amine
moieties, secondary amine moieties, or combinations of both. In
some embodiments the compound comprises two or more amine moieties
independently selected from primary amine moieties and secondary
amine moieties (polyamine). In some embodiments the compound can be
represented by a structure selected from HRN--Z and HRN--Z--NRH
where Z is a hydrocarbyl group having 1 to 20 carbon atoms and R
can be a covalent bond, H, hydrocarbyl, heterohydrocarbyl or
polyether. In some embodiments Z is a straight or branched alkane
or a straight or branched polyether. In some embodiments Z can be a
heterohydrocarbyl group. In some embodiments Z can be a polymeric
and/or oligomeric backbone. Such polymeric/oligomeric backbone can
contain ether, ester, urethane, acrylate linkages. In some
embodiments R is H. The term polyamine refers to a compound
contains more than one --NHR group where R can be a covalent bond,
H, hydrocarbyl, heterohydrocarbyl.
[0063] Some suitable amine compounds include but are not limited to
aliphatic polyamines, arylaliphatic polyamines, cycloaliphatic
polyamines, aromatic polyamines, heterocyclic polyamines,
polyalkoxypolyamines, and combinations thereof. The alkoxy group of
the polyalkoxypolyamines is an oxyethylene, oxypropylene,
oxy-1,2-butylene, oxy-1,4-butylene or a co-polymer thereof.
[0064] Examples of aliphatic polyamines include, but are not
limited to ethylenediamine (EDA), diethylenetriamine (DETA),
triethylenetetramine (TETA), trimethyl hexane diamine (TMDA),
hexamethylenediamine (NMDA), N-(2-aminoethyl)-I,3-propanediamine
(N3-Amine), N,N'-I,2-ethanediylbis-I,3-propanediamine (N4-amine),
and dipropylenetriamine. Examples of arylaliphatic polyamines
include, but are not limited to m-xylylenediamine (mXDA), and
p-xylylenediamine. Examples of cycloaliphatic polyamines include,
but are not limited to 1,3-bisaminocyclohexylamine (1,3-BAC),
isophorone diamine (IPDA), and 4,4'-methylenebiscyclohexanamine.
Examples of aromatic polyamines include, but are not limited to
diethyltoluenediamine (DETDA), m-phenylenediamine,
diaminodiphenylmethane (DDM), and diaminodiphenylsulfone (DDS).
Examples of heterocyclic polyamines include, but are not limited to
N-aminoethylpiperazine (NAEP), and 3,9-bis(3-aminopropyl)
2,4,8,10-tetraoxaspiro(5,5)undecane. Examples of
polyalkoxypolyamines where the alkoxy group is an oxyethylene,
oxypropylene, oxy-1,2-butylene, oxy-1,4-butylene or a co-polymer
thereof include, but are not limited to
4,7-dioxadecane-1,10-diamine, 1-propanamine,2,
I-ethanediyloxy))bis(diaminopropylated diethylene glycol). Suitable
commercially available polyetheramines include those sold by
Huntsman under the Jeffamine.RTM. trade name. Suitable polyether
diamines include Jeffamines.RTM. in the D, SD, ED, XTJ, and DR
series. Suitable polyether triamines include Jeffamines.RTM. in the
T and ST series.
[0065] Suitable commercially available polyamines also include
aspartic ester-based amine-functional resins (Bayer); dimer
diamines e.g. Priamine.RTM. (Croda); or diamines such as
Versalink.RTM. (Evonik).
[0066] The amine compound may include other functionalities in the
molecule. The amine compound encompasses a single compound or a
mixture of two or more amine compounds.
[0067] The isocyanate reactive component can be a thiol. In some
embodiments the thiol comprises two or more --SH moieties
(polythiol). In some embodiments the thiol comprises at least one
--SH moiety and at least another functional moiety selected from
--OH, --NH, --NH.sub.2, --COOH, or epoxide. In some embodiments the
thiol can be represented by the structure HS--Z--SH where Z is a
hydrocarbyl group, a heterohydrocarbyl group having 1 to 50 carbon
atoms. In some embodiments Z is a straight or branched alkane or a
straight or branched polyether. Some suitable thiols include but
are not limited to pentaerythritol tetra-(3-mercaptopropionate)
(PETMP), pentaerythritol tetrakis(3-mercaptobutylate) (PETMB),
trimethylolpropane tri-(3-mercaptopropionate) (TMPMP), glycol
di-(3-mercaptopropionate) (GDMP), pentaerythritol
tetramercaptoacetate (PETMA), trimethylolpropane trimercaptoacetate
(TMPMA), glycol dimercaptoacetate (GDMA), ethoxylated
trimethylpropane tri(3-mercapto-propionate) 700 (ETTMP 700),
ethoxylated trimethylpropane tri(3-mercapto-propionate) 1300 (ETTMP
1300), propylene glycol 3-mercaptopropionate 800 (PPGMP 800),
propylene glycol 3-mercaptopropionate 2200 (PPGMP 2200),
pentaerythritol tetrakis(3-mercaptobutanoate) (KarenzMT PE-1 from
Showa Denko), and soy polythiols (Mercaptanized Soybean Oil). The
term "thiol" encompasses a single thiol or a mixture of two or more
thiols.
[0068] The isocyanate reactive component can be a compound
comprising an aminoalcohol moiety. As used herein an aminoalcohol
moiety comprises at least one amino moiety and at least one
hydroxyl moiety. In some embodiments the amine group is terminal to
the aminoalcohol compound molecule. In some embodiments the amine
group is a secondary amino group on the chain of the aminoalcohol
compound molecule. In some embodiments the aminoalcohol compound
includes a terminal primary amine and a secondary amine. In some
embodiments the aminoalcohol compound can be represented by one of
the following structures: HO--Z--NH--Z--OH or
H.sub.2N--Z--NH--Z--OH or H.sub.2N--Z--(OH).sub.2 where Z is a
hydrocarbyl group and/or an heterohydrocarbyl having 1 to 50 carbon
atoms. In some embodiments Z is a straight or branched alkane or a
straight or branched polyether. In some embodiments Z contains
cycloaliphatic moiety or aryl moiety. Some suitable aminoalcohols
include but are not limited to diethanolamine, dipropanolamine,
3-amino-1,2-propanediol, 2-amino-1,3-propane diol, 2-am
iono-2-methyl-1,3-propanediol, diisopropanolamine. The aminoalcohol
compound encompasses a single compound or a mixture of two or more
aminoalcohol compounds.
Polyvinyl Acetates and Copolymers Thereof:
[0069] Suitable polyvinyl acetates to be included in the
polyisocyanate component to increase the viscosity thereof include
polyvinyl acetate homopolymers and poly (vinyl acetate/vinyl
chloride) copolymers and mixtures thereof. Co-polymers can comprise
from about 5% to 95% or from about 20% to about 80% or from about
35% to 65% or about 50% by weight of vinyl acetate with the balance
comprising vinyl chloride as the co-monomer. Other suitable
co-monomers that can be used with the vinyl acetate either in
addition to, or instead of vinyl chloride to form a suitable vinyl
acetate co-polymer to use to increase the viscosity of the
polyisocyanate are those that are known in the art to co-polymerize
with vinyl acetate. Generally, the co-polymer should form a
homogenous mixture with the polyisocyanate component, as described
in more detail below. Without wishing to be bound by theory, it is
expected that more polar co-monomers in combination with the vinyl
acetate or vinyl acetate and vinyl chloride in general will form
homogenous blends with the polymeric MDI and the polyisocyanate
pre-polymers described herein.
[0070] Suitable weight average molecular weights for the polyvinyl
acetate homopolymer are from about 5000 to 150,000 Daltons or from
about 15,000 to 35,000 Daltons. Suitable weight average molecular
weights for the vinyl acetate/vinyl chloride copolymers are from
5,000 Daltons to about 150,000 Daltons or from about 45,000 Daltons
to about 140,000 Daltons.
[0071] Suitable amounts of the polyvinyl acetates (homopolymers
and/or copolymers) to be included in the polyisocyanate component
to increase the viscosity thereof range up to 35 weight percent,
and preferably from 5 to 20 weight percent. The preferred range of
the polyvinyl acetate added to the polyisocyanate depends on the
desired viscosity. The desired viscosity depends on the
application, as well as the viscosity of the polyisocyanate
reactive component in the two-component adhesive system. As is
known in the art, generally if the viscosities of the two
components are similar, they are mixed together more easily.
Additives:
[0072] The additives disclosed herein can be contained in either or
both of the polyisocyanate component or the polyisocyanate-reactive
component (e.g. polyol or polyamine).
[0073] The curable compositions disclosed above can include a
catalyst or cure-inducing component to modify speed of the
initiated reaction. Some suitable catalysts are those
conventionally used in polyurethane reactions and polyurethane
curing, including organometallic catalysts, organotin catalysts and
amine catalysts. Exemplary catalysts include
(1,4-diazabicyclo[2.2.2]octane) DABCO.RTM. T-12 or DABCO.RTM.
crystalline, available from Evonik; DMDEE
(2,2'-dimorpholinildiethylether); DBU
(1,8-diazabicyclo[5.4.0]undec-7-ene). The curable composition can
optionally include from about 0.01% to about 10% by weight of
composition of one or more catalysts or cure-inducing components.
Preferably, the curable composition can optionally include from
about 0.05% to about 3% by weight of composition of one or more
catalysts or cure-inducing components.
[0074] The curable composition can optionally include filler. Some
useful fillers include, for example, lithopone, zirconium silicate,
hydroxides, such as hydroxides of calcium, aluminum, magnesium,
iron and the like, diatomaceous earth, carbonates, such as sodium,
potassium, calcium, and magnesium carbonates, oxides, such as zinc,
magnesium, chromic, cerium, zirconium and aluminum oxides, calcium
clay, nanosilica, fumed silicas, silicas that have been surface
treated with a silane or silazane such as the AEROSIL.RTM. products
available from Evonik Industries, silicas that have been surface
treated with an acrylate or methacrylate such as AEROSIL.RTM. R7200
or R711 available from Evonik Industries, precipitated silicas,
untreated silicas, graphite, synthetic fibers and mixtures thereof.
When used, filler can be employed in concentrations effective to
provide desired properties in the uncured composition and cured
reaction products and typically in concentrations of about 0% to
about 90% by weight of composition, more typically 1% to 30% by
weight of composition of filler. Suitable fillers include
organoclays such as, for example, Cloisite.RTM. nanoclay sold by
Southern Clay Products and exfoliated graphite such as, for
example, xGnP.RTM. graphene nanoplatelets sold by XG Sciences. In
some embodiments, enhanced barrier properties are achieved with
suitable fillers.
[0075] The curable composition can optionally include a thixotrope
or rheology modifier. The thixotropic agent can modify rheological
properties of the uncured composition. Some useful thixotropic
agents include, for example, silicas, such as fused or fumed
silicas, that may be untreated or treated so as to alter the
chemical nature of their surface. Virtually any reinforcing fused,
precipitated silica, fumed silica or surface treated silica may be
used. Examples of treated fumed silicas include
polydimethylsiloxane-treated silicas, hexamethyldisilazane-treated
silicas and other silazane or silane treated silicas. Such treated
silicas are commercially available, such as from Cabot Corporation
under the tradename CAB-O-SIL.RTM. ND-TS and Evonik Industries
under the tradename AEROSIL.RTM., such as AEROSIL.RTM. R805. Also
useful are the silicas that have been surface treated with an
acrylate or methacrylate such as AEROSIL.RTM. R7200 or R711
available from Evonik Industries. Examples of untreated silicas
include commercially available amorphous silicas such as
AEROSIL.RTM. 300, AEROSIL.RTM. 200 and AEROSIL.RTM. 130.
Commercially available hydrous silicas include NIPSIL.RTM. E150 and
NIPSIL.RTM. E200A manufactured by Japan Silica Kogya Inc. The
rheology modifier can be employed in concentrations effective to
provide desired physical properties in the uncured composition and
cured reaction products and typically in concentrations of about 0%
to about 70% by weight of composition and advantageously in
concentrations of about 0% to about 20% by weight of composition.
In certain embodiments the filler and the rheology modifier can be
the same.
[0076] The curable composition can optionally include an
antioxidant. Some useful antioxidants include those available
commercially from BASF under the tradename IRGANOX.RTM.. When used,
the antioxidant should be used in the range of about 0 to about 15
weight percent of curable composition, such as about 0.3 to about 1
weight percent of curable composition.
[0077] The curable composition can optionally include a reaction
modifier. A reaction modifier is a material that will increase or
decrease reaction rate of the curable composition. For example,
8-hydroxyquinoline (8-HQ) and derivatives thereof such as
5-hydroxymethyl-8-hydroxyquinoline can be used to adjust the cure
speed. When used, the reaction modifier can be used in the range of
about 0.001 to about 15 weight percent of curable composition.
[0078] The curable composition can optionally contain a
thermoplastic polymer in addition those described herein comprising
vinyl acetate or vinyl acetate and vinyl chloride ss polymerized
units. Non-limiting examples of suitable thermoplastic polymers
include acrylic polymer, functional (e.g. containing reactive
moieties such as --OH and/or --COOH) acrylic polymer,
non-functional acrylic polymer, acrylic block copolymer, acrylic
polymer having tertiary-alkyl amide functionality, polysiloxane
polymer, polystyrene copolymer, divinylbenzene copolymer,
polyetheramide, polyvinyl acetal, polyvinyl butyral, polyvinyl
chloride, methylene polyvinyl ether, cellulose acetate, styrene
acrylonitrile, amorphous polyolefin, olefin block copolymer [OBC],
polyolefin plastomer, thermoplastic urethane, polyacrylonitrile,
ethylene acrylate copolymer, ethylene acrylate terpolymer, ethylene
butadiene copolymer and/or block copolymer, styrene butadiene block
copolymer, and mixtures of any of the above.
[0079] The curable composition can optionally include one or more
adhesion promoters that are compatible and known in the art.
Examples of useful commercially available adhesion promoters
include amino silane, glycidyl silane, mercapto silane, isocyanato
silane, vinyl silane, (meth)acrylate silane, and alkyl silane.
Common adhesion promoters are available from Momentive under the
trade name Silquest or from Wacker Chemie under the trade name
Geniosil. Silane terminated oligomers and polymers can also be
used. The adhesion promoter can be used in the range of about 0% to
about 20% percent by weight of curable composition and
advantageously in the range of about 0.1% to about 15% percent by
weight of curable composition.
[0080] The curable composition can optionally include one or more
coloring agents. For some applications a colored composition can be
beneficial to allow for inspection of the applied composition. A
coloring agent, for example a pigment or dye, can be used to
provide a desired color beneficial to the intended application.
Exemplary coloring agents include titanium dioxide, C.I. Pigment
Blue 28, C.I. Pigment Yellow 53 and phthalocyanine blue BN. In some
applications a fluorescent dye can be added to allow inspection of
the applied composition under UV radiation. The coloring agent will
be present in amounts sufficient to allow observation or detection,
for example about 0.002% or more by weight of total composition.
The maximum amount is governed by considerations of cost,
absorption of radiation and interference with cure of the
composition. More desirably, the coloring agent may be present in
amounts of up to about 20% by weight of total composition.
[0081] The curable composition can optionally include from about 0%
to about 20% by weight, for example about 1% to about 20% by weight
of composition of other additives known in the arts, such as
tackifier, plasticizer, flame retardant, diluent, reactive diluent,
moisture scavenger, and combinations of any of the above, to
produce desired functional characteristics, providing they do not
significantly interfere with the desired properties of the curable
composition or cured reaction products of the curable
composition.
[0082] When used as an adhesive, the curable compositions can
optionally include up to 80% by weight of the total weight of the
curable composition of a suitable solvent. This type of adhesives
is known as solvent-based adhesives. Upon application of the
curable composition on a first substrate, the solvent is quickly
evaporated away, for example by heated ovens, then a second
substrate is laminated onto the curable composition coated side of
the first substrate to form a laminated structure.
Representative Procedures:
[0083] Preparation of Isocyanate Functional Material with
Viscosity-Increasing Polymers:
[0084] The isocyanate was heated to 10.degree. C. above the
softening temperature of the PVAc material in a double planetary
mixer equipped with heating and cooling. This mixing temperature
therefore ranged from 75.degree. C. to 135.degree. C. Once the
isocyanate was heated to the target temperature, the PVAc resin
(homopolymer or copolymer) was added to the isocyanate and mixed
for approximately one hour. Generally, one hour was an adequate
time to achieve a complete incorporation of the polymer comprising
as polymerized units vinyl acetate or vinyl acetate and vinyl
chloride into the isocyanate, if the isocyanate and the polymer
resin could form a homogeneous mixture. The homogeneous samples
were cooled to approximately 50.degree. C. before discharge.
[0085] The term "homogeneous" as used herein is understood to mean
that the material is single phase and predominately or completely
free from bubbles, unmixed solids, and heterogeneity upon visual
inspection and probing with a spatula after cooling. The material
appears smooth and consistent during pouring.
[0086] In order to assess long-term stability of the samples, the
samples were stored at room temperature for at least two months
under nitrogen without component separation or reaction. Some
samples have been determined to be stable for at least six months
under these conditions.
Viscosity Measurement:
[0087] Viscosities of all of the samples were measured at
25.degree. C. using a Brookfield Viscometer at 2 RPM and 20 RPM,
with RV Spindle 6. All of the viscosities reported herein are as
measured at 20 RPM.
Adhesion Under Shear:
[0088] Lap shear samples were prepared using Birch substrate TS 264
(3''.times.1''.times.0.25''), with a 0.5'' overlap, and TS 141
0.010'' spacer wire. Samples were controlled at a 1.15 index, so
mix ratio was measured by weight. Samples were added to a mixing
cup, mixed for 1 min at 1800 rpm, and added to the substrate with 2
spacer wires. Samples were left to cure for 7 days at room
temperature. Samples were pulled at 0.5 inch/min. 5 samples were
pulled and averaged. "Index" is understood to mean: (number of
isocyanate groups/number of groups reacting with the
isocyanate).times.100.
[0089] The weight percent NCO (isocyanate) as listed in the
following examples is calculated.
[0090] Materials Used in the Examples:
[0091] Particular polyisocyanate compounds used herein include the
following:
[0092] Mondur.RTM. MB: high-purity grade difunctional isocyanate,
diphenylmethane 4,4'-diisocyanate (Covestro);
[0093] Mondur.RTM. MLQ: mixture of 4,4'-methylene diphenyl
diisocyanate (MDI) and 2,4-MDI; monomer (Covestro);
[0094] Mondur.RTM. MR light, poly MDI (mixture of polymerized or
oligomerized 4,4- and 2,4 MDI (Covestro);
[0095] Mondur.RTM. CD: modified monomer, modified with carbodiimide
(Covestro); Mondur.RTM. PF: quasi-pre-polymer: ratio of
diisocyanate:polyol is greater than 2:1, i.e. there is some
monomeric diisocyanate in the mixture of polymers and oligomers
(Covestro);
[0096] Mondur.RTM. MA 2300: quasi-pre-polymer allophanate based on
4,4' diphenylmethanediisocyanate; i.e. urethane reacted with a
diisocyanate (Covestro);
[0097] Desmodur.RTM. E744: aromatic polyisocyanate pre-polymer
based on MDI and tripropylene glycol (Covestro);
[0098] Desmodur.RTM. E23A: aromatic polyisocyanate pre-polymer
based on (2,4-MDI) (Covestro).
[0099] Vinnapas.RTM. B 1.5: polyvinyl acetate homopolymer, weight
average molecular weight of 15,000 Daltons, softening temperature
of 65.degree. C. (Wacker Chemie AG);
[0100] Vinnapas.RTM. B 14: polyvinyl acetate homopolymer, weight
average molecular weight of 35,000 Daltons, softening temperature
of 101.degree. C. (Wacker Chemie AG);
[0101] Vinnol.RTM. H 40/60: 61% polyvinyl chloride/39% polyvinyl
acetate copolymer; weight average molecular weight of 120,000
Daltons (Wacker Chemie AG).
[0102] Elvax.RTM. 150: 68% polyethylene/32% vinyl acetate copolymer
(DuPont)
[0103] Elvax.RTM. 750: 91% polyethylene/9% vinyl acetate copolymer;
(DuPont)
[0104] Vitel.RTM. 7900: amorphous copolyester (Bostik)
[0105] Vylon.RTM. 245: amorphous copolyester MW=19,000 Daltons;
(Toyobo)
[0106] Vylon.RTM. 296: amorphous copolyester MW=14,000 Daltons;
(Toyobo)
[0107] All polymer molecular weights (MW) are weight average
molecular weight in Daltons.
EXAMPLES
Example 1: Effect of Type of Polyvinyl Acetate Polymer and Effect
of Molecular Weight of Polymer on Viscosity of Various
Isocyanate-Functional Materials
[0108] The following compositions were mixed according to the
general mixing procedure described above. 10% of each thermoplastic
was mixed with 90% by weight with each isocyanate composition. The
compatible mixtures were those that formed a homogeneous mixture
after approximately an hour of mixing and remained homogenous and
did not degrade, crystallize or undergo a significant change in
viscosity after at least two months of storage under nitrogen.
[0109] Properties of the particular materials used are listed
below:
[0110] The results are presented below in Table 1.
TABLE-US-00001 TABLE 1 Polyisocyanate Components Mondur Mondur
Mondur MR- Mondur Mondur Mondur MA Desmodur Desmodur MLQ Light CD
PF 2300 E744 R 23A 1 Viscosities of polyisocyanate components mixed
with polymers Isocyanate monomer polymeric monomer prepolymer
prepolymer prepolymer prepolymer prepolymer prepolymer
polisocyanate 4,4' and MDI Modified Modified allophanate TPG/MDI,
Prepolymer PPG- type 2,4 MDI micture 2,4-MDI +2,4 MDI 1000/ monomer
MDI Wt % NCO 33.6 31.5 29.5 22.9 23 23.5 15.4 12.7 Viscosity 10 250
50 700 550 750 1250 2900 (mPas) Viscosity of polyisocyanate
component with 10% by weight of polymer added (mPa s) Polymers
Vinnapas.RTM. NC 1900 NC 7350 3150 8800 4200 8750 B 1.5
Vinnapas.RTM. NC 3400 NC NT NT 14700 NT 13450 B 14 Vinnol.RTM. NT
89000 NT NT NT 288000 NT NC H 40/60 *Elvax.RTM. NC NC NC NC NC NC
NT NC 150 comparative *Elvax.RTM. NC NC NC NC NC NC NT NC 750
comparative *Vitel.RTM. NT NT NT NT NT NC NT NC 7900 comparative
*Vylon.RTM. NT NT NT NT NT NC NT NT 245 comparative *Vylon.RTM. NT
NT NT NT NT NC NT NT 296 comparative NC is not compatible or
incompatible means the mixture under the listed conditions was not
homogeneous. NT is not tested.
[0111] This example illustrates the surprising compatibility and
the viscosity-increasing ability of the polyvinyl acetate
homopolymers of a range of molecular weights and a poly (vinyl
acetate/vinyl chloride) copolymer compared to other polymers and
co-polymers of vinyl acetate.
Example 2: Effect of Polyvinyl Acetate on Viscosity of a
Pre-Polymer
[0112] Pre-polymer 1 comprising 50% polyisocyanate as Mondur.RTM.
MB (4,4'-methylene diphenyl diisocyanate, 33.6 wt. % NCO, MW=250,
functionality=2, Covestro) and 50% polypropylene glycol (ARCOL.RTM.
POLYOL PPG 1000: Molecular weight=1010.8, functionality=2) was
synthesized according to the following procedure: The pre-polymer 1
made according to this method had NCO weight % of 12.7 and a
Brookfield viscosity at 25.degree. C. of 2900 mPasec using spindle
6 at 20 RPM.
[0113] 50% by weight of MDI (4,4'-methylene diphenyl diisocyanate
as Mondur.RTM. MB from Covestro) was melted at 50.degree. C. prior
to use. The melted MDI was charged into a reactor at 70.degree. C.
Then 50% by weight of PPG (polypropylene glycol as ARCOL.RTM.
POLYOL PPG 1000) was added to the reactor. These reactants were
mixed at 70.degree. C. for 1 hour under nitrogen, and then packaged
under nitrogen.
[0114] The following samples were prepared by making a 20 percent
by weight polyvinyl acetate masterbatch of pre-polymer 1 according
to the general mixing procedure described above and then diluting
the masterbatch as necessary with pre-polymer 1.
[0115] The viscosity was measured with a Brookfield rheometer at 20
rpm using spindle 6. The percent NCO shown in the table is
calculated. The composition of the mixtures and the obtained
viscosities are shown below in Table 2:
TABLE-US-00002 TABLE 2 Viscosity of pre-polymer 1 with various
amounts of added polyvinyl acetate. Viscosities are reported in mPa
s. 2 3 4 5 6 Mondur .RTM. MB 50.0% 47.5% 45.0% 42.5% 40.0% PPG-1000
50.0% 47.5% 45.0% 42.5% 40.0% Vinnapas .RTM. B 1.5 0.0% 5.0% 10.0%
15.0% 20.0% total 100 100 100 100 100 Wt % NCO 12.7 12.0 11.4 10.8
10.2 (calculated) Viscosity 6/20 2900 5200 8600 12,800 32,400 mPa
sec Increase N/A 79 197 341 1017 in viscosity
[0116] The viscosity of the prepolymer 1 as a function of the
amount of added polyvinyl acetate is shown in FIG. 1.
Example 3: Effect of Polyvinyl Acetate on Viscosity of a
Quasi-Pre-Polymer
[0117] Example 3 is similar to Example 2, except that a
quasi-pre-polymer was used instead of the prepolymer1. The
quasi-pre-polymer used was Desmodur.RTM. E-744 (Covestro). Desmodur
E-744 contains significant amounts of monomeric 2,4 MDI in addition
to an isocyanate functional prepolymer. The various samples were
made according to the same procedure described in Example 2, i.e. a
masterbatch was prepared according to the general procedure and
then diluted as necessary with the quasi-pre-polymer to obtain the
desired weight percent of polyvinyl acetate.
[0118] The results are shown in Table 3 and the viscosity of the
Desmodur.RTM. E-744 in mPas as a function of the amount of
polyvinyl acetate is shown in FIG. 2. The viscosity was measured
with a Brookfield rheometer at 20 rpm using spindle 6. The percent
NCO shown in the table is calculated.
TABLE-US-00003 TABLE 3 Viscosity of quasi-pre-polymer Desmodur
.RTM. E-744 with various amounts of added polyvinyl acetate.
Viscosities are reported in mPa s. 7 8 9 10 11 Desmodur .RTM. E-744
100.0 95.0 90.0 85.0 80.0 Vinnapas .RTM. B 1.5 0.0% 5.0% 10.0%
15.0% 20.0% total 100 100 100 100 100 Wt % NCO 23.5 22.3 21.1 20.0
18.8 (calculated) Viscosity 6/20 750 2600 8800 25,200 45,100 (mPa
sec) Increase in N/A 247 1073 3260 5913 viscosity (%)
[0119] Surprisingly, while monomeric 2,4 MDI does not exhibit
thickening effects the Desmodur E-744 containing a significant
amount of monomeric 2,4 MDI in addition to an isocyanate functional
prepolymer thickened appreciably.
Example 4: Effect of Polyvinyl Acetate on Viscosity of Polymeric
MDI
[0120] Example 4 is similar to Example 3, except that a polymeric
MDI was used instead of the quasi-pre-polymer. The polymeric MDI
that was used was a commercially available product, Mondur.RTM.
MR-Light (Covestro). The various samples were made according to the
same procedure described in Example 2, i.e. a masterbatch was
prepared according to the general procedure and then diluted as
necessary with the polymeric MDI to obtain the desired weight
percent of polyvinyl acetate.
[0121] The results are shown below in Table 4 and the viscosity of
Mondur.RTM. MR-Light in mPas as a function of the amount of added
polyvinyl acetate is shown in FIG. 3. The viscosity was measured
with a Brookfield rheometer at 20 rpm using spindle 6. The percent
NCO shown in the table is calculated.
TABLE-US-00004 TABLE 4 Viscosity of polymeric MDI Mondur .RTM.
MR-Light with various amounts of added polyvinyl acetate. 12 13 14
15 16 Mondur .RTM. MR-Light 100.0 95.0 90.0 85.0 80.0 Vinnapas
.RTM. B 1.5 0.0% 5.0% 10.0% 15.0% 20.0% Wt % NCO 31.5 29.2 28.4
26.8 25.2 (calculated) Viscosity 6/20 500 700 1900 5500 15,100 (mPa
sec) Increase in N/A 40 280 1010 2920 viscosity, (%)
Example 5: Shear Adhesion of Polyurethane Samples Comprising
Polyvinyl Acetate
[0122] Various polyisocyanate/polyvinyl acetate compositions,
prepared according to the general procedure, were mixed with the
polyol component of a standard two-component polyurethane adhesive
(Loctite.RTM. UK U-05FL, Henkel) in order to evaluate the effect of
the polyvinyl acetate on the shear adhesion of the two-component
polyurethane adhesive composition. The relative amounts of
polyisocyanate/polyvinyl acetate component and polyol component of
the Loctite.RTM. UK U-05FL were selected to obtain an isocyanate
index of 1.15 (i.e. the molar ratio of isocyanate groups to
hydroxyl groups was 1.15:1). The lap shear strength of the samples
were measured and compared to the standard two component adhesive
Loctite.RTM. UK U-05FL.
[0123] The samples were prepared and tested as follows:
[0124] Lap shear samples were prepared using birch substrate and
spacer wire. Samples were controlled at a 1.15 Index, so the mix
ratio was measured by weight. Adhesive samples were prepared by
adding the appropriate amounts of the polyisocyanate/polyvinyl
acetate component and the Loctite.RTM. UK U-05FL polyol component
to a mixing cup, and then mixing for 1 minute at 1800 rpm. These
adhesive samples were then applied in between two pieces of the
birch substrate (3''.times.1''.times.0.25'' South End Wood Working
and Supply), with a 0.5'' overlap. Two spacer wires 0.010'' from
Atlantic Precision Spring were placed in the adhesive of each
overlapped area. The samples were left to cure for 7 days at room
temperature and then tested.
[0125] These samples were pulled at 1.27 cm/min and the lap shear
strength in mPa was recorded. Five samples of each adhesive sample
were pulled and the averages for each composition are reported in
Table 3 along with the standard deviation.
TABLE-US-00005 TABLE 5 Lap shear strength in m Pa Polyisocyanate
component Loctite.RTM. UK U-05FL Desmodur.RTM. Mondur.RTM.
Mondur.RTM. comparative E744 Mondur.RTM. PF 2300 MR-Light
Prepolymer 1 PVAc resin None 11.46 .+-. 0.09 N/A N/A N/A N/A N/A
10% Vinnepas.RTM. N/A 6.34 .+-. 0.61 8.34 .+-. 0.59 9.75 .+-. 0.54
5.27 .+-. 0.72 2.6 .+-. 0.49 B1.5 20% Vinnepas.RTM. N/A 4.41 .+-.
0.54 not measured not measured not measured not measured B1.5 10%
Vinnepas.RTM. N/A 6.35 .+-. 0.63 not measured not measured not
measured not measured B13
[0126] These results show that the properties of the adhesive are
not deteriorated by the presence of the polyvinyl acetate polymer.
The reduction of the properties of the adhesive are due only to the
expected dilution of the polyisocyanate component.
[0127] In some embodiments, the invention herein can be construed
as excluding any element or process step that does not materially
affect the basic and novel characteristics of the composition or
process. Additionally, in some embodiments, the invention can be
construed as excluding any element or process step not specified
herein.
[0128] Although the invention is illustrated and described herein
with reference to specific embodiments, the invention is not
intended to be limited to the details shown. Rather, various
modifications may be made in the details within the scope and range
of equivalents of the claims and without departing from the
invention.
[0129] Within this specification, embodiments have been described
in a way which enables a clear and concise specification to be
written, but it is intended and will be appreciated that
embodiments may be variously combined or separated without
departing from the invention. For example, it will be appreciated
that all preferred features described herein are applicable to all
aspects of the invention described herein.
* * * * *